Speed regulator for internal combustion engines



Oct. 8, 1935. E. BoUDlN SPEED REGULATOR FOR ITERNAL COMBUSTION ENGINES 2sheets-sheet 1 Filed Aug. 8, 1935 INVENTOI Oct. 8, 1935. E. BoUDlN lSPEED REGULATOR FOR INTERNAL COMBUSTION ENGINES Filed Aug. 8, 1933 2Sheets-Sheet 2 y l l l l Idlfl I I l Il Edgard BOLLCL'UL INVEN'TORlwhich is based upon the vacuum existing in Patented Oct. 8, 1935 SPEEDREGULATOR FOR INTERNAL COMBUSTION ENGINES Edgard Boudin, Brussels,Belgium Application In PATENT OFFICE August 8', 1933,A Serial No.684,167 Germany August 15, 1932 zciaims. (c1. 13u-15s) The presentinvention relates to a speed regulator for internal combustion engines.The principle of the speed regulator for internal combustion engines,the automatic action of depression or partial the admission pipes of thefuel gases and the atmospheric pressure is already well known. A shutteror cut-off organ is inserted in the said piping and is actuated andcontrolled by By referring to means of a suitable mechanism.

the diagram shown in Figure 5 it will be seen that a curve Arepresenting the partial vacuum created in the supply piping of a motor,shows the effect of a shutter or cut-oir beginning of cates thedepression or from O to OI, the supply the carburetter. The the saidcurve (abscissee O) indipartial vacuum created (starting from theordinate D which is equal to the atmospheric pressure) at a fulladmission,

when the motor works i. e. full load. For a comparatively large amountof throttling the depression does not increase denly but further onenormously or sud- (up to the abscissae Ol which represents the minimumcross sectional area of admission c-a-al, that is to say,

that cross sectional area which corresponds to the no-load running ofthe motor) the said depression or partial vacuum rises suddenly. Thiscurve -A represents the partial vacuum above the cut-off member orshutter provided between the admission pipe of the engine and theCarburettor.

depression existing below the said cut-olf member or throttle and shownby the curve B gradually and progressively decreases as the passage ofthe admission channels is throttled more and more.

The deformation of any kind within the limits of its of spring is,elasticity or resiliency,

proportional to the load applied to said spring. Obviously if a springis used -to counteract and counterbalance any kind jected to and ofdevice which is subacted upon by the variable depression or partialvacuum, which varies according to resultant of the two curves springwill on like A and B, the said ly be able to equalize or balance thesaid depression or partial vacuum for one value quite inadequate for(for instance for lthe value correa fully open admission) but will beother values. Therefore, a

series of springs would be required, the resistance of which would havecurve of to be adjusted in successive would have to follow as closely asthe depression or partial h a device, the adjustment of which v2' whichare in fact constituted 'end shields 3 and 4 end capped in an airtightmanner by means of vthe spring covers 5 and 6. thus apparatus airtight.Y 55 would be a very diicult and delicate matter, does however notpossess the characteristic features which are a sine qua non conditionof its successful application.

The essential feature of the present invention 5 consists mainly in acorrecting device for speed regulators which renders it possible to varythe resistance opposed to the depression or partial vacuum existing inthe admission piping of the engine, and to do this in such a manner asto 10 counterbalance the cut-off or shutter in its Various positions ofthrottling the passage area of the gas or fuel gas supply pipes.

This correcting device will act upon the spring in such a manner thatthe adequate resistance l5 is obtained which is required tocounterbalance the system by imparting to it a variable iiexibility withrespect to the depression or partial vacuum curve.

The appended drawings illustrate a preferred 20 embodiment of theinvention which is in no way limited to it, by way of example.

In these drawings Figure 1 shows a plan View of the speed regulator andalso in a longitudinal section; Figure 2 shows the same regulating de-25 vice in an elevation and in a longitudinal section passing throughthe axis of the cut-0E member. or throttle, the latter shown asthrottling the admission to the permissible maximum amount, that is tosay, the cross-sectional area ofthe 30 gaseous fuel supply adapted tothe running of the motor at no load. The drawings furthermore show howthe regulating device is interposed between the admission piping denotedby M and the carburetter C with its butterfly valve 31.

Figure 3 shows a cross-section of the regulator according to the line:c-y of Figure 4, and Figure `4 shows an elevation ofthe said regulatoras seen from outside, whereas Figure 5 shows the housing l which isbored out on its whole length Yfor the purpose of accommodating thecut-off shutter or throttle consisting of two parts 2 and by twopistons. 45 Owing to the fact that these pistons are adapted to movetowards one another, they effect the throttling of the cross sectionalarea of the bore forming the extension of the admission pipe of theengine to the carburetter (Figure 2). This 50 body or housing I isclosed at each end by the and the whole is at each making the'whole Theabove mentioned housing I is moreover provided with another bore, withinwhich the valve l of the corrector device is suitably mounted togetherwith its adjusting and regulating devices 27, 28, 29. A channel 8 putsthe internal face of each piston 2 and 2 into communication by means ofthe passages 8', 8, 8.

The valve 7 communicates with the atmosphere by means of the orifice 24and the apparatus is airtight so long as the valve 'I is not lifted offits seat 25.

The pistons 2 and 2 are provided with slots which enable them to slidealong the pins or bolts 9 and Iil. It will be seen in Figure 2, Y(onwhich the cut-01T or throttle member is purposely shown in its closedposition) that the slot H corresponding to the piston 2 uncovers theport I2 provided in one of the overlapping lips of the said slots.

The piston 2 is provided with a rod I3 ywith suitable adjustable locknuts I4 thus allowing its travel or stroke to be regulated, whereas thepiston 2 has a constant stroke or travel which is determined by thelength of its' slot abutting on the rod 9. Each of the pistons 2 and 2is rigidly mounted on and therefore integral with the screw threadedrods I5, I6, I'l which allow them to be held back by means of thetension springs I8, I9, 2li, which are supported by and rest against theend covers 3 and l the springs being adapted to be screwed into them.Each of the rods I8, I9 and 29 are threaded at one of their extremitieson to which nuts and lock nuts 2|, 22, 23, are screwed. This arrangementenables the resilience of these springs to be varied according to theeffective number of turns and to their individual tension.

The correcting device consists of the double acting valve 'l which isadapted according to requirements either to throttle the air supplycoming through the inlet orice 2Q by sitting either on its seat 25 or onits seat 26. A regulating spring 2l is adapted to have its tensionadjusted to the proper amount by means of the rectilinear displacementof its supporting sleeve or collar 28 by adjusting the stationary screw29. The resilience of the spring 2'I is attained by screwing the turnsof this spring more or less into the nut of the valve 'l in the samemanner as it is done by screwing the springs I8, I9, 20 into the covers3 and 4. The air which is admitted into the apparatus at the givenmoment so as to enable it to act on the pistons 2 and 2 thus enters theapparatus through the valve 'I passes then through 8 thus penetratinginto the interior of the piston 2, then passes into the channel 8through 8 and finally enters into the interior of the piston 2 throughthe passage 8".

When the piston 2 has during its course of travel uncovered the port I2a part of the air admitted by the valve 'l passes over into theadmission pipe of the engine. As this air however is only admittedthereinto at high loads it exercises no appreciable influence on thecarburizing process and may be considered to come from a carburettertted with a diffuser having a diameter a few tenths of millimetres inexcess of the diameter that would ordinarily have been chosen.

It is possible to regulate the quantity of air passing through the valve'I by regulating the adjustable air passage I2 in respect to theposition of the piston I 2.

It is thus easily seen that the air taken in at atmospheric pressure maydrop in pressure within the interior of the apparatus to such extentthat it assists the spring in neutralizing or counteractlng the actionof the partial vacuum acting on the external surface of the cutting-offor throttling pistons 2 and 2. The pistons may, therefore, assume aposition giving a clear passage area to the carburetted gases inproportion to the partial vacuum which varies according to 5 the numberof revolutions of the engine, thus allowing just sufcient gas to pass tokeep up the required output of the motor.

Fig. 3 shows the cross section of the regulator along the engine gasfeed line. 10 As shown in Fig. 2, M is adjacent the extension of theengine gas feed line, and C is adjacent the connection between thecarburetor and the regulator. 'Ihrough an opening 33 the internal faceof valve 'I (Fig. 1) communicates with the engine 15 gas feed linethrough a channel which divides into two branches. These open at 34, Mto the engine gas feed side and at 35, C to the carburetor side (seealso Fig. 2). By means of a screw 35 the cross section of the channelmay be varied at 34 20 with respect to the cross section at 35.

This adjustment makes possible the accurate control of valve 'l (Fig. l)for slight engine variations as indicated by curves A and B in Fig. 5.The start of the curve (abscissa O) indicates the 25 depression producedat the highest permissible engine speed. If for any reason the enginespeed increases, the depression also increases to a certain extent. I'hepurpose of the regulator is to prevent such increase .and it mustimmediately 30 begin to function to diminish the gas feed sufciently forslowing down the motor but only t0 a point near the permissible speed.Curve A shows that when the gas feed is constricted the depressionincreases considerably above the regu- 35 lator (at M).

Curve B shows that in response to such constriction the depression onthe carburetor side (at C) diminishes quite fast. If, therefore, thechannel connecting the valve 'I with the gas feed line 40 is subjectedonly to the influence of the depression at M, the valve will bemaintained open when the depression is many times greater than theinitial depression which exists in the gas 'feed line at full enginespeed. The engine must be slowed 45 down considerably to reestablishthis initial depression when the pistons 2 and 2 are close together andnot when they are apart and permit gas to flow. The engine will slowdown because, as shown by curve A, approach of the pistons to 50 oneanother increases the depression at a given speed.

If the connection between valve l and the gas feed opened only on thecarburetor side C and behaved only as shown by curve B, then for a 55given constriction of the gas` feed the depression would diminish andwould rapidly approach atmospheric pressure. Thus the valve i would beunder the influence of a lower depression than the one causing itsinitial opening. Spring 27 50 would close the valve and pistons 2 and 2would go apart. The engine would again speed up, the valve 'I wouldreopen, gas feed diminish, etc., etc. Owing to this pumping actionstable engine speeds could not be maintained. 55

Owing to the fact that the regulator is open to the engine andcarburetor sides, by means of the adjusting screw 26 the flow from C toM may be maintained at a steady rate. The intensity of the ,m iiow willbe suiicient to keep the valve I open when the engine is slowed down toor maintained at the predetermined speed. The valve responds to everypressure Variation and opens more or less to admit Variable quantitiesof atmospheric air. ,I5

. the two curves A and B of the diagram in Fig- The closing of thecut-off member or shutter is limited by the abutment |3-I4 in such amanner that the maximum engine speed is obtained at no-load. When,therefore, the cut-off member or shutter tends to attain this limit, theengine will be slowed down. If the latter is working against a constantresistance the cut-off member being in a state of equilibrium opensproportionally and stabilizes the cross sectional area of this orifice.On the other hand, if this resistance increases, the pistons 2 and 2recede from one another and the partial vacuum acting on the valve 1reaches the value existing at C as well as in M, and if the resistancedrops below the value which caused the valve 1 to open, it will beunbalanced and pressed on its seat 25 thus causing uniform and equalpressure to exist in the whole apparatus. The springs then cause thecomplete reopening of the pistons 2 and 2. If one starts from the slowspeed of the engine, c-a-d, with the butterfiy valve 31 nearlycompletely closed, then the latter causes in the piping and consequentlyalso in the regulator a considerable'partial vacuum, which exerts a verygreat tractive effort on the valve 1 lowering the latter. on to its seat2B thus shutting off the admission of air in the same way as it doeswhen it sits on its seat 25. This arrangement is provided so that noquantity of supplementary air in excess of that passing through thecarbureter can enter, whereby the slowing down will be regulated. Whenthe butterfly valve 31 is opened, this partial vacuum decreases and at acertain moment the valve 1 passes from one of its seats to the other andshuts o upto the moment when the regulator is again called into action.

The valve 1 instantly responds to the control and it is possible toapply the total motor couple in one single acceleration effect.

Assuming for example an engine which must not exceed a speed of 2500revolutions, the valve will be adjusted so as to open at a speed of 2350revolutions. The spring of the piston 2 will be adjusted so as tobalance the valve at this particular number of revolutions, and thepiston 2 will be set to operate at 2400 revolutions. If this speed isexceeded the two pistons close, and if the resistance, i. e. the load onthe engine, diminishes to no-load the cut-off member or shutter willremain in the closed position which it asumes at 2500 revolutions. Ifthe engine attains under load a speed of 2500 revolutions and the sameload remains, the cut-off or shutter is balanced at a speed of about2400 to 2350 revolutions and opens more and more as the load increases.

In a cut-off or shutter device having two pistons it is possible to makeuse of the nature of ure 5 so as to obtain a certain corrective actionon the springs. The outer faces of the pistons have a slope which duringoperation produces a V shaped opening whereby one half of the piston 5faces are influenced at a certain moment which they approach oneanother, viz: the top half by the effects according to curve A and theother half by the effect according to curve B.

With pistons having annular semi-circular 10 faces on their top half,the surfaces may be varied, the remaining portion of these facesreceding with respect to these segments, and thus share the influence ofthe curve B. The nearer segments are subject to the influence of 15 thecurve A which may be a means to vary the tractive effort due to thepartial vacuum which influences consequently these pistons.

It is moreover possible to utilize the difference of pressure drop orpartial vacuum which may 20 exist above the corrective device (curve A)and below it (curve B).

What I claim is:-

1. In a speed regulator for internal combustion engines having acarburetor with fuel feed lines 25 and a channel for conductingcombustible gases to the engine, a cylinder in said channel andsubstantially at right angles to the latter, two opposed pistons in saidcylinder and having outside faces, means comprising a valve forselectively 30 exposing said outside faces to the atmosphere and to thepressure in said channel, an adjustably tensioned spring forcounterbalancing said valve, two branches leading from said channel andconnecting said pistons on one side with said chan- 35 nel and on theother side with the fuel feed lines of the carburetor, means for varyingthe crosssection of'one branch with respect to the cross section of theother branch, the degrees of opening of said valve being determined bythe dif- 4,0 ference between atmospheric pressure and gas pressure insaid channel, and by the depression produced by the passage of gasthrough said branch, said depression depending in turn on the positionof said pistons, and means for independ- 45 ently and separatelyadjusting said pistons.

2. A speed regulator according to claim 1 and in which said pistons havedifferential internal faces in different planes, whereby for certaindegrees of throttling of said channel, a variable sur- 50 face of eachpiston is subjected to the depression existing in said channel on oneside of said pistons and the balance of said surface is subjected to thedepression existing on the other side of said pistons. 55

EDGARD BOUDIN.

